The Somerset herald. [volume] (Somerset, Pa.) 1870-1936, 1887-09-14
Wood Preservation.

WOOQ PT0S0f tdtiOIl.
For many years there were many COM
plants and dissatisfaction with modern
ships in the navy because of their early
decay, resulting from law of nature
which has never been entirely overcome.
Many unsuccessful efforts have been
made 10 do this, but thus far practical
tests have not demonstrated the thor
ough efficiency of any of them. The pro-
cess of preservation as applied at the
| Charlestown Navy Yard, adopted in ls1771
gives the most satisfactory results, great
.ly increasing the durability Of the wood.
The creosote process was applied TO sew
eral ships and, although meeting all the
requirements of preseryative, it emitted
strong odor which tainted ali the food
on board ship, rendering it 50 distasteful
+ that IL could not be eaten. For this rea-
son il was found necessary 10 abandon
this process. The chemicals used in the
present method of preserving do not
smell bad, and after exposure to air or
water for few weeks there is none what
ever 1t is admitted that this process is
superior to all others, and as il may be of
interest to many of our readers, here ap-
pended is given the method OF timber
preservation by impregnation at the
Chsrlestown Navy Yard.
Timber of all dimensions is loaded on
cars, which are run into copper cylin-
der six feet in diameter and eighty feet
IN length. A pipe leads from the bottom
of the copper boiler 10 a steam boiler
this pipe is pierced with numerous small
holes to permit the free escape of the
steam. Steam is then admitted which
will thoroughly saturate the timber,
pressing cut the sap, with the exception
of some of its albumen parts, which, to-
gether with the condensed water, will
run of at the bottom ofthe copper cylin-
der The steam answers the double pur-
pose Of driving out the sap, and at the
same time rendering the timber, which,
as found in the market, cannot be expect
ed always TO be evenly seasoned, uni
formly prepared to receive the impreg-
nation. The gate at the end of the boil
er being Theoretically sealed makes the
huge cylinder perfectly air tight. Now
powerful air pump, connected with the
cylinder, Is set IN oper Ition, for the
double purpose of extracting the con-
densed steam contained in the timber
and of extracting the air 10 form yacu-
um. When the vacuum i established
the copper cylinder is filled with a solu-
ton Of sulphate of copper, and by means
of d force pump pressure of from 100 to
10 pounds TO the square inch is applied.
After the timber is saturated with sui
phate of copper the residuum is let off
and vacuum is formed again and so
luton of chloride of barium is admitted.
This forms in a short time a chemical
combination with the sulphate of copper,
forming insoluable salt of sulphate of
barytes, and the timber is then ready for
use
The destruction of all wooden struct-
ures in salt water by the ship worm is
only question Of time when the wood
has not been impregnated. When the
temperature of the ocean is high this
ship worm will destroy wooden struct-
ures so thoroughly in two years that
they become thereby unfit and unsafe for
use, and have to be renewed. All efforts
TO stop the action of these microbes fail
ed until this process was introduced.
Many failed partly because the nature of
some application was either such that
they would not enter into the green,
sappy wood, or that they washed out ca
silly by the action of the water, and part
ly because such applications were confin-
ed TO an outside coating. which, when
removed from any one given point, af-
forded no protection, for worm after
worm then entered, and the whole stick
was quickly destroyed. Even to case a
whole pile with sheet copper is only
temporary, though costly remedy, for
only so long as the whole arnor remains
intact and ineloses the stick in water
tight manner is il protected.
The nature of the process here describ-
ed is such that sticks OF any length, even
when cut the same day, can easily be i'm
pregnated thoroughly from one end TO
the other, and the crystals precipitated
along the inside of the pores ofthe wood,
rs the result of the combination Of the
two chemicals, form a coating inside
these pores, which neither can be re-
moved by mechanical action nor the ac-
ton of water, as sulphate of barytes is
insoluble in water or acids. Soft wood.
such as pine, whitewood, beech, etc,
which, when unprepared, only last from
two to three years, has been found when
prepared by this process to be in good
condition after sixteen years service
Railroad ties which have been impreg-
mated have been found free from decay
after exposure for fifteen years. which tes-
titles to the efficiency OF ilnpregnation
Boston H1llafacsarers' Gd-sffs.